John 17:22-24… 22 The glory which You have given Me I have given to them, that they may be one, just as We are one; Jesus continues saying this unity will reveal His love for the people of the world.
2 Samuel is a story of disunity that interfered with Israel A being a kingdom of priests. Chapter 20 is filled with drama that requires some background. Look for these main characters: David, Joab, Abishai, Amasa, and Sheba. Who were the antagonists-villains or protagonists-heroes?
1010 BC David made King over Judah after death of Saul and Jonathan. Joab was David’s commander, Joab, Abishai, and Asahel, brothers, were David’s nephews. [1 Chronicles 2:13-16].
1008 BC There was a civil war between Joab and Abner. Abner kills Asahel, Joab’s brother.
1005 BC David agrees to cooperate with Abner to unite tribes, but Joab murders Abner [2 Samuel 2:18-23, 3:27-34]
1003 BC Tribes finally united David reigns over all 12 tribes of Israel
993 BC David seduces Bathsheba, has Joab murder her husband, Uriah the Hittite one of David’s 37 mighty men, and marries her. Ahithophel was Bathsheba’s grandfather.
991 BC God forgave David but promised “the sword shall never depart from your house” 2 Samuel 12:10a
986 BC Amnon, Davids son, rapes his half-sister Tamar and Absalom kills his half-brother Amnon. 2 Samuel 13
976 BC Absalom conspires to take the kingdom from David 2 Samuel 15. Ahithophel betrays David and joins Absalom. Amasa also betrays David and becomes commander of Absalom’s army; he was a nephew of David, and cousin of Joab, as well as a cousin of Absalom, David’s son. David leaves Jerusalem in humility trusting God for the outcome good or bad.
972 BC the spy Hushai’s warning saves David and his army; Ahithophel commits suicide, Joab, Abishai & Ittai share command of the troops for David, Joab kills Absalom; 20,000 troops killed and David returns to Jerusalem. 2 Samuel 17-19
Wow; when I write this web of family intrigue and betrayal it is sobering. Certainly the sword never left David’s house over 19 years from 991BC, there is a consequence even to confessed sin.
There was so much disunity the focus was inward to Israel rather than outward as a kingdom of priests to other nations. However, David’s humility set the example for us and also his personally attracting non-Israelites like Ittai!
Notes: A- “Israel” is used in three ways:  for the 12 tribes of Israel that were united under Joshua, David and Solomon,  for what is known as the northern tribes without Judah and sometimes Benjamin and  the area occupied by the people returning from captivity by Babylon and Persia and the government formed in May 1948. For Tribal map of Israel in time of Joshua click here; and David and Solomon click here, the timeline in the upper left corner is very badly off.